1. Field of the Invention
The present invention relates to a surgical needle for suturing a tissue in a surgical operation and particularly, to a surgical needle having a significantly small resistance when going through a tissue enabling to reduce strength required of a surgeon and a method for producing the surgical needle as well as a needle holder for holding the needle to be grasped by the surgeon.
2. Description of the Prior Art
The technology to apply a high frequency current between an tip of a surgical needle and a tissue of an organ so as to create a hallow portion for passing the surgical needle is suggested, for example, Japanese Patent Laid-Open Hei 9-19436.
In this technology, a surgical needle is wrapped by insulating means excluding its tip and tail so that the tail is clamped by a needle holder which is connected to a high frequency power source so as to apply a high frequency current to the tip of the surgical needle. The high frequency current is carried between a tissue of an organ and the tip of the surgical needle so as to apply a high temperature heat to a portion where the tip of the surgical needle has approached so that a cavity is created in the tissue, enabling to pass the surgical needle through with a small load applied.
Because a high frequency current is applied to the surgical needle, the tail to be clamped by the needle holder is electrically exposed without any insulating material, and the tail portion to be clamped by the needle holder is predetermined in the design stage.
However, when carrying out a surgical operation in an abdomen of a patient having various complicated organs, a surgeon should handle the surgical needle and the needle holder within a limited range. The aforementioned conventional surgical needle has a problem that it is difficult to handle the surgical needle because a predetermined position of the surgical needle should be clamped by the needle holder and the surgeon cannot move the surgical needle as he/she wishes.
It can also be considered to design the tail portion without insulation larger than usual so as to increase the range of the surgical needle which can be clamped by the needle holder. In such a case, however, the tail of the surgical needle is brought into contact with a tissue of an organ before the tip of the surgical needle has passed through the tissue. In such a state, the high frequency current from the needle holder flows directly into the tissue of the patient so as to heat a portion of the tissue to be left as a cavity. Moreover, this current leak causes insufficient high frequency current applied to the tip of the surgical needle, disabling, in some cases, to pass through the tissue.
It is also considered to prepare a plurality of surgical needles, each having a different length of a tail without insulation so that they can be used according to the actual operation conditions. However, there are various types and various configurations of the surgical needle, and it is practically impossible to vary the tail length for each of the types and each of the configurations.